4 files changed, 45 insertions, 9 deletions
diff --git a/guides/source/action_cable_overview.md b/guides/source/action_cable_overview.md
index 7809607574..77a1b73bae 100644
--- a/guides/source/action_cable_overview.md
+++ b/guides/source/action_cable_overview.md
@@ -151,7 +151,7 @@ established using the following JavaScript, which is generated by default by Rai
 // Action Cable provides the framework to deal with WebSockets in Rails.
 // You can generate new channels where WebSocket features live using the `rails generate channel` command.
 
-import ActionCable from "actioncable"
+import ActionCable from "@rails/actioncable"
 
 export default ActionCable.createConsumer()
 ```
diff --git a/guides/source/action_mailbox_basics.md b/guides/source/action_mailbox_basics.md
index eb8a14b4d2..c5ec921ad5 100644
--- a/guides/source/action_mailbox_basics.md
+++ b/guides/source/action_mailbox_basics.md
@@ -20,8 +20,8 @@ Introduction
 
 Action Mailbox routes incoming emails to controller-like mailboxes for
 processing in Rails. It ships with ingresses for Amazon SES, Mailgun, Mandrill,
-and SendGrid. You can also handle inbound mails directly via the built-in
-Postfix ingress.
+Postmark, and SendGrid. You can also handle inbound mails directly via the
+built-in Postfix ingress.
 
 The inbound emails are turned into `InboundEmail` records using Active Record
 and feature lifecycle tracking, storage of the original email on cloud storage
@@ -155,6 +155,42 @@ would look like this:
 $ URL=https://example.com/rails/action_mailbox/postfix/inbound_emails INGRESS_PASSWORD=... rails action_mailbox:ingress:postfix
 ```
 
+### Postmark
+
+Tell Action Mailbox to accept emails from Postmark:
+
+```ruby
+# config/environments/production.rb
+config.action_mailbox.ingress = :postmark
+```
+
+Generate a strong password that Action Mailbox can use to authenticate
+requests to the Postmark ingress.
+
+Use `rails credentials:edit` to add the password to your application's
+encrypted credentials under `action_mailbox.ingress_password`,
+where Action Mailbox will automatically find it:
+
+```yaml
+action_mailbox:
+  ingress_password: ...
+```
+
+Alternatively, provide the password in the `RAILS_INBOUND_EMAIL_PASSWORD`
+environment variable.
+
+[Configure Postmark inbound webhook](https://postmarkapp.com/manual#configure-your-inbound-webhook-url)
+to forward inbound emails to `/rails/action_mailbox/postmark/inbound_emails` with the username `actionmailbox`
+and the password you previously generated. If your application lived at `https://example.com`, you would
+configure Postmark with the following fully-qualified URL:
+
+```
+https://actionmailbox:PASSWORD@example.com/rails/action_mailbox/postmark/inbound_emails
+```
+
+NOTE: When configuring your Postmark inbound webhook, be sure to check the box labeled **"Include raw email content in JSON payload"**.
+Action Mailbox needs the raw email content to work.
+
 ### SendGrid
 
 Tell Action Mailbox to accept emails from SendGrid:
diff --git a/guides/source/active_record_basics.md b/guides/source/active_record_basics.md
index a67e2924d7..b0d4bbd2c0 100644
--- a/guides/source/active_record_basics.md
+++ b/guides/source/active_record_basics.md
@@ -105,9 +105,9 @@ depending on the purpose of these columns.
   fields that Active Record will look for when you create associations between
   your models.
 * **Primary keys** - By default, Active Record will use an integer column named
-  `id` as the table's primary key. When using [Active Record
-  Migrations](active_record_migrations.html) to create your tables, this column will be
-  automatically created.
+  `id` as the table's primary key (`bigint` for Postgres and MYSQL, `integer`
+  for SQLite). When using [Active Record Migrations](active_record_migrations.html)
+  to create your tables, this column will be automatically created.
 
 There are also some optional column names that will add additional features
 to Active Record instances:
diff --git a/guides/source/active_storage_overview.md b/guides/source/active_storage_overview.md
index 51f50e8931..6d07d34dd7 100644
--- a/guides/source/active_storage_overview.md
+++ b/guides/source/active_storage_overview.md
@@ -489,7 +489,7 @@ directly from the client to the cloud.
     Using the npm package:
 
     ```js
-    import * as ActiveStorage from "activestorage"
+    import * as ActiveStorage from "@rails/activestorage"
     ActiveStorage.start()
     ```
 
@@ -616,7 +616,7 @@ of choice, instantiate a DirectUpload and call its create method. Create takes
 a callback to invoke when the upload completes.
 
 ```js
-import { DirectUpload } from "activestorage"
+import { DirectUpload } from "@rails/activestorage"
 
 const input = document.querySelector('input[type=file]')
 
@@ -664,7 +664,7 @@ will call the object's `directUploadWillStoreFileWithXHR` method. You can then
 bind your own progress handler on the XHR.
 
 ```js
-import { DirectUpload } from "activestorage"
+import { DirectUpload } from "@rails/activestorage"
 
 class Uploader {
   constructor(file, url) {